FACTSHEETCORAL REEFSTHREATENEDOFF BRITAIN

October 2001

Although coral reefs are normally associated withthe tropics, they exist in cold water too. TheDarwin Mounds, a deep-lying collection ofhundreds of sand and cold water coral moundsnorth of Scotland, are an example. They wereonly discovered in 1998 and have already beendamaged.

Chart showing the location of the Darwin Mounds (Courtesyof DEEPSEAS Group, Southampton Oceanography Centre).

Lophelia pertusa colonies and associated benthic faunaphotographed on the Darwin Mounds (Courtesy ofDEEPSEAS Group, © Southampton Oceanography Centre).

Where are the Darwin Mounds?

Part of an underwater landscape north of Scotland,the Darwin Mounds are situated in the north-eastcorner of the Rockall Trough immediately to thesouth of the Wyville Thomson Ridge. About185 km north west of Cape Wrath, they are withinthe United Kingdom’s 200 nautical mile offshorewaters. Their protection is therefore theresponsibility of the UK government.

How big are the Darwin Mounds?

The Darwin Mound fields spread acrossapproximately 100 km2. There are hundreds ofindividual mounds that are typically circular inoutline and up to 5 m high and 100 m across.

Why are they so precious?

Under current knowledge the Darwin Mounds areunique. They appear to be sand volcanoes and haveunique tails, up to several hundred metres inlength, downstream of the principal currentdirection. The tails are characterised by a very high

abundance of giant one-celled animals(protozoans), called xenophyophores. The singlecells may grow to more than 20 cm and are oftenfragile. On the mounds themselves, substantialpopulations of the deep-water coral Lopheliapertusa are present in the form of colonies of a fewto several metres wide. Deep sea fish such as theroundnose grenadier and the cut throat eel frequentthe mounds. The mounds also provide shelter andhabitat for many more animals including somespecies of sponges, starfish and echiuran worms.Thus, more species are present at the DarwinMounds as compared to the surrounding seabed.

Specimens of the xenophyophore Syringammina fragilissimarecovered in core samples from the Darwin Mounds area(Courtesy of DEEPSEAS Group, © SouthamptonOceanography Centre).

Darwin Mounds under threat

There is evidence that the mounds have beenimpacted by fishing gear since their discovery in1998. High frequency sonar observations ofDarwin Mounds show seabed scars, some of whichtrack directly through the mounds. Photographshave revealed areas of smashed and fragmentedcoral that are the direct result of trawling. Thedestruction coincides with observed fishing activityin the region by EU vessels registered outside theUK. It is of particular note that all but one of thedeep-sea fish stocks such as the roundnosegrenadier found in the vicinity of the DarwinMounds have no current management system inplace at all. Deep-sea fish live in a comparatively

low energy environment, which is reflected in theirslow rate of growth and reproduction. Sustainableexploitation rates will be very low. Scientistsrecommend a suite of management measures suchas fishing licenses, closed areas and gearrestrictions rather than catch quotas.

Offshore mineral mining is another potential threatto sensitive offshore habitats such as the DarwinMounds. The 19th Round of Offshore Oil and Gaslicensing announced earlier this year focused onthe Atlantic Frontier to the north west of Scotland.It took a cautious route and avoided licensing anyblocks in the vicinity of the Darwin Mounds.While it is currently unlikely, no protection is inplace to ensure that a licensing decision for the seaareas including the Darwin Mounds is notapproved in the future.

High frequency sidescan sonar images of Darwin Mounds.(a) An apparently ‘intact’ mound. (b) A mound that appearsto have been disrupted by deep-water commercial trawling.(Courtesy of Dr Andrew Wheeler, University College, Cork,and Dr Doug Masson, Southampton Oceanography Centre, ©University College, Cork).

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Darwin Mounds conservation status

The Darwin Mounds comprise a unique underwaterreef habitat that should qualified as an offshoreSpecial Area of Conservation (SAC) under theEuropean Union’s Habitats Directive.

Following a UK High Court decision in 1999, theBritish government is in the process of reviewingoffshore habitats for identifying a network ofmarine SACs to comply with the Directive. Muchwork needs to be undertaken throughout Europe inorder to conserve habitats and species offshore andthe UK Government are at the forefront ofidentifying offshore SACs. While there is littledoubt that the Darwin Mounds should beconserved under the Habitats Directive, no actionhas yet been taken to protect them.

What needs to be done to save the DarwinMounds

The next steps in protecting the Darwin Moundsinclude designation of the Darwin Mounds SAC,drawing up a management plan for the site andimplementing the management plan.

Successful long-term conservation of habitats suchas the Darwin Mounds will include themanagement of fishing under the EU CommonFisheries Policy and managing the cumulativeeffects of oil and gas production and otheractivities under UK legislation. It is of note thatwhile it is probably EU fishing trawlers registeredoutside the UK that have damaged the DarwinMounds to date, action is required by the UKGovernment. The UK Government needs toidentify the management action required for theDarwin Mounds and to make a proposal formanagement to the European CommissionDirectorate General for Fisheries (DG Fish).

WWF is one of the world's largest and most experienced independentconservation organizations with almost five million supporters and a globalnetwork active in more than 90 countries.

WWF's mission is to stop the degradation of the planet's natural environmentand to build a future in which humans live in harmony with nature, by:- conserving the world's biological diversity- ensuring that the use of renewable natural resources is sustainable- promoting the reduction of pollution and wasteful consumption.

© 2001 WWF North-East Atlantic Programmehttp://www.wwfneap.org

Text by: Sarah Jones & Anthony Snape

This briefing was prepared by Sabine Christiansen & Silvia Hoffmann

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